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Ecological Networks


We use network analysis and mathematical modeling to understand and quantify the structure, dynamics, and function of biological communities, including their responses to environmental changes such as species extinctions, invasions, climate change, and fisheries. This research program has contributed a more mechanistic understanding of the structure and dynamics of ecological networks, a better integration between theoretical and empirical research in network ecology, and a more predictive theory to evaluate the responses of entire biological communities to environmental change.

Latest Publications

The role of intra-guild indirect interactions in assembling plant-pollinator networks

Dritz, S., Nelson, R.A., Valdovinos, F.S. 2023; Nature Communications

"Understanding the assembly of plant-pollinator communities has become critical to their conservation given the rise of species invasions, extirpations, and species’ range shifts. Over the course of assembly, colonizer establishment produces core interaction patterns, called motifs, which shape the trajectory of assembling network structure. Dynamic assembly models can advance our understanding of this process by linking the transient dynamics of colonizer establishment to long-term network development. In this study, we investigate the role of intra-guild indirect interactions and adaptive foraging in shaping the structure of assembling plant-pollinator networks by developing: 1) an assembly model that includes population dynamics and adaptive foraging, and 2) a motif analysis tracking the intra-guild indirect interactions of colonizing species throughout their establishment. We find that while colonizers leverage indirect competition for shared mutualistic resources to establish, adaptive foraging maintains the persistence of inferior competitors. This produces core motifs in which specialist and generalist species coexist on shared mutualistic resources which leads to the emergence of nested networks. Further, the persistence of specialists develops richer and less connected networks which is consistent with empirical data. Our work contributes new understanding and methods to study the effects of species’ intra-guild indirect interactions on community assembly." 


Figure 1) Each of our four guiding questions corresponds with a stage in core motif development

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